initial letch support, fix capture in logic sim

src/kyupy/circuit.py

@@ -256,14 +256,14 @@ class Circuit:
         yielded first.
         """
         visit_count = [0] * len(self.nodes)
-        queue = deque(n for n in self.nodes if len(n.ins) == 0 or 'DFF' in n.kind)
+        queue = deque(n for n in self.nodes if len(n.ins) == 0 or 'dff' in n.kind.lower())
         while len(queue) > 0:
             n = queue.popleft()
             for line in n.outs:
                 if line is None: continue
                 succ = line.reader
                 visit_count[succ] += 1
-                if visit_count[succ] == len(succ.ins) and 'DFF' not in succ.kind:
+                if visit_count[succ] == len(succ.ins) and 'dff' not in succ.kind.lower():
                     queue.append(succ)
             yield n
 
@@ -282,13 +282,13 @@ class Circuit:
         yielded first.
         """
         visit_count = [0] * len(self.nodes)
-        queue = deque(n for n in self.nodes if len(n.outs) == 0 or 'DFF' in n.kind)
+        queue = deque(n for n in self.nodes if len(n.outs) == 0 or 'dff' in n.kind.lower())
         while len(queue) > 0:
             n = queue.popleft()
             for line in n.ins:
                 pred = line.driver
                 visit_count[pred] += 1
-                if visit_count[pred] == len(pred.outs) and 'DFF' not in pred.kind:
+                if visit_count[pred] == len(pred.outs) and 'dff' not in pred.kind.lower():
                     queue.append(pred)
             yield n
 
@@ -310,21 +310,21 @@ class Circuit:
 
     def fanout_free_regions(self):
         for stem in self.reversed_topological_order():
-            if len(stem.outs) == 1 and 'DFF' not in stem.kind: continue
+            if len(stem.outs) == 1 and 'dff' not in stem.kind.lower(): continue
             region = []
-            if 'DFF' in stem.kind:
+            if 'dff' in stem.kind.lower():
                 n = stem.ins[0]
-                if len(n.driver.outs) == 1 and 'DFF' not in n.driver.kind:
+                if len(n.driver.outs) == 1 and 'dff' not in n.driver.kind.lower():
                     queue = deque([n.driver])
                 else:
                     queue = deque()
             else:
                 queue = deque(n.driver for n in stem.ins
-                              if len(n.driver.outs) == 1 and 'DFF' not in n.driver.kind)
+                              if len(n.driver.outs) == 1 and 'dff' not in n.driver.kind.lower())
             while len(queue) > 0:
                 n = queue.popleft()
                 preds = [pred.driver for pred in n.ins
-                         if len(pred.driver.outs) == 1 and 'DFF' not in pred.driver.kind]
+                         if len(pred.driver.outs) == 1 and 'dff' not in pred.driver.kind.lower()]
                 queue.extend(preds)
                 region.append(n)
             yield stem, region

src/kyupy/logic.py

@@ -291,6 +291,23 @@ def mv_xor(x1, x2, out=None):
     return out
 
 
+def mv_latch(d, t, q_prev, out=None):
+    """A latch that is transparent if `t` is high. `q_prev` has to be the output value from the previous clock cycle.
+    """
+    m = mv_getm(d, t, q_prev)
+    d, t, q_prev = mv_cast(d, t, q_prev, m=m)
+    out = out or MVArray(np.broadcast(d.data, t.data, q_prev).shape, m=m)
+    out.data[...] = t.data & d.data & 0b011
+    out.data[...] |= ~t.data & 0b010 & (q_prev.data << 1)
+    out.data[...] |= ~t.data & 0b001 & (out.data >> 1)
+    out.data[...] |= ((out.data << 1) ^ (out.data << 2)) & 0b100
+    unknown = (t.data == UNKNOWN) \
+              | (t.data == UNASSIGNED) \
+              | (((d.data == UNKNOWN) | (d.data == UNASSIGNED)) & (t.data != ZERO))
+    np.putmask(out.data, unknown, UNKNOWN)
+    return out
+
+
 def mv_transition(init, final, out=None):
     """Computes the logic transitions from the initial values of ``init`` to the final values of ``final``.
     Pulses in the input data are ignored. If any of the inputs are ``UNKNOWN``, the result is ``UNKNOWN``.
@@ -460,3 +477,27 @@ def bp_xor(out, *ins):
         out[..., 0, :] |= any_unknown
         out[..., 1, :] &= ~any_unknown
         out[..., 2, :] &= ~any_unknown
+
+
+def bp_latch(out, d, t, q_prev):
+    md = out.shape[-2]
+    assert md == d.shape[-2]
+    assert md == t.shape[-2]
+    assert md == q_prev.shape[-2]
+    if md == 1:
+        out[...] = (d & t) | (q_prev & ~t)
+    elif md == 2:
+        any_unknown = t[..., 0, :] ^ t[..., 1, :]
+        any_unknown |= (d[..., 0, :] ^ d[..., 1, :]) & (t[..., 0, :] | t[..., 1, :])
+        out[...] = (d & t) | (q_prev & ~t)
+        out[..., 0, :] |= any_unknown
+        out[..., 1, :] &= ~any_unknown
+    else:
+        any_unknown = (t[..., 0, :] ^ t[..., 1, :]) & ~t[..., 2, :]
+        any_unknown |= ((d[..., 0, :] ^ d[..., 1, :]) & ~d[..., 2, :]) & (t[..., 0, :] | t[..., 1, :] | t[..., 2, :])
+        out[..., 1, :] = (d[..., 1, :] & t[..., 1, :]) | (q_prev[..., 0, :] & ~t[..., 1, :])
+        out[..., 0, :] = (d[..., 0, :] & t[..., 0, :]) | (out[..., 1, :] & ~t[..., 0, :])
+        out[..., 2, :] = out[..., 1, :] ^ out[..., 0, :]
+        out[..., 0, :] |= any_unknown
+        out[..., 1, :] &= ~any_unknown
+        out[..., 2, :] &= ~any_unknown

src/kyupy/logic_sim.py

@@ -30,15 +30,22 @@ class LogicSim:
         self.circuit = circuit
         self.sims = sims
         nbytes = (sims - 1) // 8 + 1
-        self.interface = list(circuit.interface) + [n for n in circuit.nodes if 'dff' in n.kind.lower()]
+        dffs = [n for n in circuit.nodes if 'dff' in n.kind.lower()]
+        latches = [n for n in circuit.nodes if 'latch' in n.kind.lower()]
+        self.interface = list(circuit.interface) + dffs + latches
+
         self.width = len(self.interface)
         """The number of bits in the circuit state (number of ports + number of state-elements)."""
+
         self.state = np.zeros((len(circuit.lines), mdim, nbytes), dtype='uint8')
         self.state_epoch = np.zeros(len(circuit.nodes), dtype='int8') - 1
         self.tmp = np.zeros((5, mdim, nbytes), dtype='uint8')
         self.zero = np.zeros((mdim, nbytes), dtype='uint8')
         self.epoch = 0
 
+        self.latch_dict = dict((n.index, i) for i, n in enumerate(latches))
+        self.latch_state = np.zeros((len(latches), mdim, nbytes), dtype='uint8')
+
         known_fct = [(f[:-4], getattr(self, f)) for f in dir(self) if f.endswith('_fct')]
         self.node_fct = []
         for n in circuit.nodes:
@@ -69,6 +76,9 @@ class LogicSim:
         """
         for node, stim in zip(self.interface, stimuli.data if hasattr(stimuli, 'data') else stimuli):
             if len(node.outs) == 0: continue
+            if node.index in self.latch_dict:
+                self.latch_state[self.latch_dict[node.index]] = stim
+            else:
                 outputs = [self.state[line] if line else self.tmp[3] for line in node.outs]
                 self.node_fct[node]([stim], outputs)
             for line in node.outs:
@@ -83,13 +93,27 @@ class LogicSim:
 
     def capture(self, responses):
         """Capture the current values at the primary outputs and in the state-elements (flip-flops).
+        For primary outputs, the logic value is stored unmodified in the given target array.
+        For flip-flops, the logic value is constructed from the previous state and the new state.
 
         :param responses: A bit-parallel storage target for the responses in a compatible shape.
         :type responses: :py:class:`~kyupy.logic.BPArray`
         :returns: The given responses object.
         """
         for node, resp in zip(self.interface, responses.data if hasattr(responses, 'data') else responses):
-            if len(node.ins) > 0: resp[...] = self.state[node.ins[0]]
+            if len(node.ins) == 0: continue
+            if node.index in self.latch_dict:
+                resp[...] = self.state[node.outs[0]]
+            else:
+                resp[...] = self.state[node.ins[0]]
+            if self.m > 2 and 'dff' in node.kind.lower() and len(node.outs) > 0:
+                if node.outs[0] is None:
+                    resp[1, :] = ~self.state[node.outs[1], 0, :]  # assume QN is connected, take inverse of that.
+                else:
+                    resp[1, :] = self.state[node.outs[0], 0, :]
+                resp[..., 2, :] = resp[..., 0, :] ^ resp[..., 1, :]
+                # We don't handle X or - correctly.
+
         return responses
 
     def propagate(self, inject_cb=None):
@@ -116,7 +140,8 @@ class LogicSim:
             if self.state_epoch[node] != self.epoch: continue
             inputs = [self.state[line] if line else self.zero for line in node.ins]
             outputs = [self.state[line] if line else self.tmp[3] for line in node.outs]
-            # print('sim', node)
+            if node.index in self.latch_dict:
+                inputs.append(self.latch_state[self.latch_dict[node.index]])
             self.node_fct[node](inputs, outputs)
             for line in node.outs:
                 if inject_cb is not None: inject_cb(line, self.state[line])
@@ -179,6 +204,12 @@ class LogicSim:
         if len(outputs) > 1:
             logic.bp_not(outputs[1], inputs[0])
 
+    @staticmethod
+    def latch_fct(inputs, outputs):
+        logic.bp_latch(outputs[0], inputs[0], inputs[1], inputs[2])
+        if len(outputs) > 1:
+            logic.bp_not(outputs[1], inputs[0])
+
     @staticmethod
     def nand_fct(inputs, outputs):
         logic.bp_and(outputs[0], *inputs)

src/kyupy/techlib.py

@@ -33,12 +33,14 @@ class TechLib:
             if pin[0] == 'A': return int(pin[1])
             if pin[0] == 'B': return int(pin[1]) + int(kind[4])
         for prefix, pins, index in [('HADD', ('B0', 'SO'), 1),
-                                    ('MUX21', ('S',), 2),
+                                    ('MUX21', ('S', 'S0'), 2),
                                     ('MX2', ('S0',), 2),
                                     ('TBUF', ('OE',), 1),
                                     ('TINV', ('OE',), 1),
-                                    ('DFF', ('QN',), 1),
+                                    ('LATCH', ('D',), 0),
+                                    ('LATCH', ('QN',), 1),
                                     ('DFF', ('D',), 0),
+                                    ('DFF', ('QN',), 1),
                                     ('SDFF', ('D',), 0),
                                     ('SDFF', ('QN',), 1),
                                     ('SDFF', ('CLK',), 3),

tests/test_logic.py

@@ -145,6 +145,20 @@ def test_mv_operations():
     assert lg.mv_xor(x1_4v, x2_4v)[0] == '0XX1XXXXXXXX1XX0'
     assert lg.mv_xor(x1_8v, x2_8v)[0] == '0XX1PRFNXXXXXXXXXXXXXXXX1XX0NFRPPXXNPRFNRXXFRPNFFXXRFNPRNXXPNFRP'
 
+    x30_2v = lg.MVArray("0000", m=2)
+    x31_2v = lg.MVArray("1111", m=2)
+    x30_4v = lg.MVArray("0000000000000000", m=4)
+    x31_4v = lg.MVArray("1111111111111111", m=4)
+    x30_8v = lg.MVArray("0000000000000000000000000000000000000000000000000000000000000000", m=8)
+    x31_8v = lg.MVArray("1111111111111111111111111111111111111111111111111111111111111111", m=8)
+
+    assert lg.mv_latch(x1_2v, x2_2v, x30_2v)[0] == '0001'
+    assert lg.mv_latch(x1_2v, x2_2v, x31_2v)[0] == '1011'
+    assert lg.mv_latch(x1_4v, x2_4v, x30_4v)[0] == '0XX00XXX0XXX0XX1'
+    assert lg.mv_latch(x1_4v, x2_4v, x31_4v)[0] == '1XX01XXX1XXX1XX1'
+    assert lg.mv_latch(x1_8v, x2_8v, x30_8v)[0] == '0XX000000XXXXXXX0XXXXXXX0XX10R110XX000000XXR0R0R0XXF001F0XX10R11'
+    assert lg.mv_latch(x1_8v, x2_8v, x31_8v)[0] == '1XX01F001XXXXXXX1XXXXXXX1XX111111XX01F001XXR110R1XXF1F1F1XX11111'
+
 
 def test_bparray():
 
@@ -212,3 +226,27 @@ def test_bparray():
     assert lg.MVArray(out_2v)[0] == '0110'
     assert lg.MVArray(out_4v)[0] == '0XX1XXXXXXXX1XX0'
     assert lg.MVArray(out_8v)[0] == '0XX1PRFNXXXXXXXXXXXXXXXX1XX0NFRPPXXNPRFNRXXFRPNFFXXRFNPRNXXPNFRP'
+
+    x30_2v = lg.BPArray("0000", m=2)
+    x30_4v = lg.BPArray("0000000000000000", m=4)
+    x30_8v = lg.BPArray("0000000000000000000000000000000000000000000000000000000000000000", m=8)
+
+    lg.bp_latch(out_2v.data, x1_2v.data, x2_2v.data, x30_2v.data)
+    lg.bp_latch(out_4v.data, x1_4v.data, x2_4v.data, x30_4v.data)
+    lg.bp_latch(out_8v.data, x1_8v.data, x2_8v.data, x30_8v.data)
+
+    assert lg.MVArray(out_2v)[0] == '0001'
+    assert lg.MVArray(out_4v)[0] == '0XX00XXX0XXX0XX1'
+    assert lg.MVArray(out_8v)[0] == '0XX000000XXXXXXX0XXXXXXX0XX10R110XX000000XXR0R0R0XXF001F0XX10R11'
+
+    x31_2v = lg.BPArray("1111", m=2)
+    x31_4v = lg.BPArray("1111111111111111", m=4)
+    x31_8v = lg.BPArray("1111111111111111111111111111111111111111111111111111111111111111", m=8)
+
+    lg.bp_latch(out_2v.data, x1_2v.data, x2_2v.data, x31_2v.data)
+    lg.bp_latch(out_4v.data, x1_4v.data, x2_4v.data, x31_4v.data)
+    lg.bp_latch(out_8v.data, x1_8v.data, x2_8v.data, x31_8v.data)
+
+    assert lg.MVArray(out_2v)[0] == '1011'
+    assert lg.MVArray(out_4v)[0] == '1XX01XXX1XXX1XX1'
+    assert lg.MVArray(out_8v)[0] == '1XX01F001XXXXXXX1XXXXXXX1XX111111XX01F001XXR110R1XXF1F1F1XX11111'

tests/test_logic_sim.py

@@ -73,6 +73,41 @@ def test_8v():
         assert resp[i] == mva[i]
 
 
+def test_loop():
+    c = bench.parse('q=dff(d) d=not(q)')
+    s = LogicSim(c, 2, m=8)
+    assert len(s.interface) == 1
+    mva = MVArray([['0'], ['1']], m=8)
+
+    s.assign(BPArray(mva))
+    s.propagate()
+    resp_bp = BPArray((len(s.interface), s.sims))
+    s.capture(resp_bp)
+    resp = MVArray(resp_bp)
+
+    assert resp[0] == 'R'
+    assert resp[1] == 'F'
+
+    resp_bp = s.cycle(resp_bp)
+    resp = MVArray(resp_bp)
+
+    assert resp[0] == 'F'
+    assert resp[1] == 'R'
+
+
+def test_latch():
+    c = bench.parse('input(d, t) output(q) q=latch(d, t)')
+    s = LogicSim(c, 8, m=8)
+    assert len(s.interface) == 4
+    mva = MVArray(['00-0', '00-1', '01-0', '01-1', '10-0', '10-1', '11-0', '11-1'], m=8)
+    exp = MVArray(['0000', '0011', '0100', '0100', '1000', '1011', '1111', '1111'], m=8)
+
+    resp = MVArray(s.cycle(BPArray(mva)))
+
+    for i in range(len(mva)):
+        assert resp[i] == exp[i]
+
+
 def test_b01(mydir):
     c = bench.load(mydir / 'b01.bench')